The present invention relates to a method and an apparatus for setting stator coils on a blade of an inserter. Furthermore, the present invention pertains to a method for manufacturing a rotating electrical machine including a stator core about which stator coils are wound.
A stator used for a rotating electrical machine such as an electric motor and a generator has a stator core including teeth. Stator coils are inserted in slots formed between the teeth. Japanese Patent No. 3448204, Japanese Patent No. 3144759, Japanese Patent No. 3673330, Japanese Patent No. 3673337, and Japanese Laid-Open Patent Publication No. 2005-184887 disclose methods for winding stator coils. In these methods, the stator coils are wound around a stator core such that each stator coil extends over a number of teeth. The stator coils overlap one another to form a spiral shape as a whole.
Japanese Laid-Open Patent Publication No. 2005-80356 discloses a method for inserting stator coils in slots of a stator core using an inserter.
In a case where the stator coils are inserted in the slots of the stator core using the inserter, the stator coils that are formed into a predetermined shape in advance need to be set on a blade of the inserter. In order to apply the inserter to the methods disclosed in the above-mentioned Japanese Patent No. 3448204, etc., it is necessary to set, on the blade, the stator coils that are formed into a shape that permits the stator coils to overlap one another to form a spiral shape when inserted in the slots of the stator.
However, in the conventional methods, since the stator coils are manually arranged on the blade, the arrangement of the stator coils inserted in the slots tends to be uneven. In particular, unevenness in the arrangement is significant at the region where the stator coil that is set on the blade first overlaps the stator coil that is set on the blade last. The uneven arrangement of the stator coils reduces the efficiency of the rotating electrical machine.
The above-mentioned Japanese Patent No. 3144759, Japanese Patent No. 3673330, Japanese Patent No. 3673337, and the Japanese Laid-Open Patent Publication No. 2005-184887 disclose methods for mounting the stator coils on the stator core without using an inserter. The above-mentioned Japanese Patent No. 3144759 discloses a stator core, which is manufactured by combining a yoke with an iron core. The iron core includes an inner cylinder and protrusions, which extend radially outward from the inner cylinder. The protrusions are arranged at equal intervals in the circumferential direction. After sequentially setting the stator coils on the protrusions, the iron core is fitted in the yoke, which forms an outer cylinder. In this case, the inserter need not be used.
Furthermore, the above-mentioned Japanese Patent No. 3673330, Japanese Patent No. 3673337, and Japanese Laid-Open Patent Publication No. 2005-184887 disclose methods for manufacturing a single stator core by combining divided cores. More specifically, the stator core is manufactured by setting the stator coils, which are formed into a predetermined shape, on the divided cores in advance, and thereafter combining the divided cores. In this case also, the inserter need not be used. However, the stator core manufactured by combining the iron core and the yoke or the stator core manufactured by combining the divided cores reduces the efficiency of the rotating electrical machine as compared to an integrated stator core.
Accordingly, it is an objective of the present invention to evenly arrange stator coils when the stator coils are mounted on a stator core using an inserter in a state where the stator coils overlap one another to form a spiral shape.